1. Field of the Invention
The present invention relates generally to a compression system and specifically to an improved compression system that may be used for natural gas production.
2. Description of the Prior Art
Gas that comes directly from the ground (“raw natural gas”) comprises various substances. Some substances are liquid and others are non-liquids. Prior to being transmitted through a gas pipeline, it is desirable to remove liquids from the gas so that the gas can be compressed and transported through the pipeline. Liquids can include water, natural gas condensate, and oil. Raw natural gas may also typically include contaminants such as carbon dioxide (CO2) and hydrogen sulfide (H2S).
Raw natural gas is collected from a well or group of wells. This raw gas is initially processed near the collection point. There, water, oil, natural gas condensate, and other liquids are removed from the raw product and the gas is prepared for transport to a gas processing plant for further processing.
During this initial stage, natural gas compressors are used. A compressor increases the pressure of the gas by reducing its volume so that the gas can be more readily transported through a pipe. In addition to initial compression activities performed at or near the wellsite, gas compressors are also used throughout the transportation pipeline to maintain sufficient pressure to deliver the gas to a desired location.
Prior art gathering compression systems are freestanding systems comprising scrubbers adapted to remove liquids, and compressors adapted to compress natural gas. Conventional scrubbers receive an inlet stream of raw natural gas. Because liquid descends and gas rises, within the scrubber, liquid particles fall from the inlet stream and exit the bottom of the scrubber. The scrubbed gas (gas resulting from a scrubbing treatment) exits through a scrubbed gas outlet.
The scrubbed natural gas is then compressed. As compressing natural gas causes the temperature of the gas to rise, it is desirable to cool the gas before releasing the gas to the transportation pipeline. Therefore, gas exiting the compressor travels through one or more heat exchange units comprising cooler coils.
The engine, scrubber, compressor, and heat exchange units are often mounted on a skid to permit the system to be readily constructed, delivered to the compression site, and removed when desired.
Prior art natural gas compression systems are often inefficient and expensive. What is needed is a natural gas compression system that efficiently and effectively scrubs, compresses, and cools natural gas.